基于Fluent软件的束腰型生物质粉燃烧机温度场、污染物排放模拟研究

Simulation study of temperature field and pollutant emission of thin waist type biomass powder combustion machine based on Fluent

文章针对一种额定喂料量为150 kg/h的束腰型生物质粉燃烧机,通过建立其数学模型,基于Fluent软件研究不同束腰型结构倾角、束腰口间距和过量空气系数等参数对束腰型生物质粉燃烧机燃烧性能的影响。研究结果表明:束腰型生物质粉燃烧机出火口的物质的平均质量浓度和CO浓度均比直筒型生物质粉燃烧机低,当束腰型结构倾角分别为15,30,45,60°时,CO浓度仅为直筒型生物质粉燃烧机的5%,2.6%,2.8%和1.6%;当束腰口间距分别为0.4,0.5,0.6,0.7 m时,束腰型生物质粉燃烧机出火口的物质的平均质量浓度以及CO2和O2浓度相差不大,但是,随着束腰口间距的增大,平均温度呈现出先升高后降低的变化趋势;随着过量空气系数的增大,出火口的平均温度以及CO,CO2和NO浓度显著减小,物质的平均质量浓度和O2浓度有所增大;当束腰型结构倾角为30°,束腰口间距为0.5 m,过量空气系数为1.2时,束腰型生物质粉燃烧机的燃烧效果较好。

Based on the established mathermatical model of a thin waist type biomass powder combustion machine with capacity of 150 kg/h,Fluent was used to analysis the effects of different thin waist structure inclination angle,thin waist mouth diameter and excess air coefficient on the combustion performance.The results showed:The average mass concentration and the concentration of CO at the outlet of the fire mouth of the thin waist type biomass powder combustion machine are lower than that of the straight cylinder combustion machine,when the thin waist structure inclination angle is 15,30,45,60°,the concentration of CO is only 5%,2.6%,2.8%and 1.6%of the straight cylinder combustion machine,respectively.When thin waist mouth diameter is 0.4,0.5,0.6,0.7 m,respectively,there was no significant difference in the average mass concentration and the concentration of CO2 and O2 at the outlet of the thin waist type biomass powder combustion machine.However,with the increase of the thin waist mouth diameter,the average temperature increased firstly and then decreased.With the increase of excess air coefficient,the average temperature of the fire mouth and the concentrations of CO,CO2 and NO decrease significantly,the average mass concentrationl and the concentration of O2 increased.When the thin waist structure inclination angle is 30°,the thin waist mouth diameter is 0.5 m,and the excess air coefficient is 1.2,the combustion effect of the thin waist type biomass powder combustion machine is better.